Paxlovid and molnupiravir substantially reduced hospitalization and death from Omicron variants

September 21, 2023

New research conducted by the UNC Gillings School of Global Public Health and the Cleveland Clinic shows that ritonavir-boosted nirmatrelvir (Paxlovid) and molnupiravir (Lagevrio) substantially reduced COVID-19 hospitalization and death among high-risk patients, even against the most recent Omicron subvariants BQ.1.1 and XBB.1.5.   

Dr. Danyu Lin

In collaboration with researchers from the Cleveland Clinic Health System, Dr. Danyu Lin, PhD, Dennis Gillings Distinguished Professor of Biostatistics, published a new study this week in JAMA Network Open, furthering the research into the treatment of COVID-19 with the two antiviral drugs.    

The University of North Carolina at Chapel Hill began working on molnupiravir back in 2016 and demonstrated the drug could be vital in the fight against coronaviruses and future pandemics. Molnupiravir was initially discovered at Emory University and designed to combat the influenza (flu) virus. However, animal testing at the UNC Gillings School of Global Public Health, Vanderbilt University and Emory showed that it blocked transmission of the virus that causes COVID-19.   

This large cohort study covered new omicron subvariants and provided precise estimates of treatment effects for participant groups by age, race, ethnicity, date of diagnosis, vaccination status, previous infection status and coexisting conditions. The use of both antiviral drugs was associated with a substantial reduction of death and hospitalization in patients infected with new omicron subvariants. As a result, both drugs can be used for non-hospitalized patients who are at a high risk of developing severe COVID-19.   

“Our findings about the effectiveness of molnupiravir are particularly important because nirmatrelvir has significant drug-drug interactions with concomitant medications and the effectiveness of molnupiravir for high-risk patients was largely unknown,” says Lin.  

“These results are consistent with previous clinical trial data from unvaccinated individuals when the Delta variant was prevalent and underscore the importance of observational studies to assess effectiveness of COVID-19 treatments in real world settings,” says Professor Michael Hudgens, Chair of the UNC Department of Biostatistics.  

Other researchers involved in the study include Francois Abi Fadel, MD; Shuaiqi Huang, PhD; Alex T. Milinovich, MS; Gretchen L. Sacha, PharmD; Patricia Bartley, MD; Abhijit Duggal, MD; Xiaofeng Wang, PhD, all from the Cleveland Clinic.  

In a companion study published last week, this group of researchers did not find evidence that the monoclonal antibody bebtelovimab affected the risk of hospitalization or death after infection with the BA.4/BA.5 and BQ.1/BQ.1.1 subvariants. 

Dr. Lin is also a member of the Lineberger Comprehensive Cancer Center and a member of the Center for AIDS Research. He has published several high-profile papers on the effectiveness of COVID-19 vaccines and boosters in New England Journal of Medicine and JAMA.

Contact the UNC Gillings School of Global Public Health communications team at sphcomm@unc.edu.